The present invention relates generally to impact monitoring systems including impact sensors on flexible substrates. In such a system, the flexible substrate including the impact sensor can be coupled with a wearable article of protective equipment and can wirelessly communicate with a computing device, such as a smartphone or the like.
Effort has been directed towards the development of printed electronics using conventional printing technologies. Examples of such printed electronics include, organic thin film transistors (“OTFTs”) fabricated using inkjet printing, flexible displays made by means of screen printing, and electrochemical sensors fabricated by rotogravure printing. The use of printing technologies can overcome some of the drawbacks associated with conventional silicon technology, which may involve high-vacuum and high-temperature deposition processes, along with sophisticated photolithographic patterning techniques. The advantages of printing include improved cost efficiency, reduction of material wastage during fabrication, variation in compatible substrate materials, including flexible materials, and low manufacturing temperatures. These advantages have led to the research of traditional printing techniques for the manufacture of flexible impact sensors.
Interest exists in the development of impact sensors on flexible substrates for applications in the aerospace, automotive, and biomedical engineering fields. Impact sensors can be manufactured using conventional CMOS processes which are often expensive and require fabrication on rigid substrates. Accordingly, many impact sensing systems utilize hanging structures or cavity based sensor design configurations, which may include accelerometers, for example. However, further developments are desired to offer greater flexibility, stability and conformability, which may be advantageous for various impact sensing applications, including the use on protective equipment for the human body, including various pieces of sports equipment, such as helmets or the like.